1. Field of the Invention
The present invention relates to a method of detecting an erroneous connection in the case of erroneously connecting lines of ignition devices arranged in respective cylinders in an engine having a plurality of cylinders, and an apparatus of the same, and more particularly to a method for detecting an erroneous connection in the case of erroneously connecting a line for transmitting an ignition signal from an ignition device for a predetermined cylinder, in place of another line for another cylinder, in a fuel injection control apparatus of an engine utilizing ignition signals of ignition devices as reference timings of fuel injection timings, and an apparatus for executing the method.
2. Description of Related Art
Conventionally, in a fuel injection system of a general-purpose engine having a comparatively compact and simple structure, data for comprehending the operating state of the engine such as a crank angle position, an engine speed or the like, is generally is used for each of controls by detecting ignition signals of magnet type ignition devices by a fuel injection control apparatus, without using any special crank angle sensor.
For example, the fuel injection control for each cylinder in the engine has a fuel injection control apparatus which detects a primary side voltage signal of an ignition device, generates a valve opening signal using this signal as a reference timing so as to output it to an injector of each cylinder, and executes the fuel injection control, as described in Japanese Unexamined Patent Publication No. 6-10746.
In the control apparatus mentioned above, in the case of an engine having a plurality of cylinders in which interval between respectively successive ignition timings for the cylinders are different, ignition devices 2 and 3 are respectively necessary for the cylinders having the different injection timings, such as in a fuel injection system shown in FIG. 5, and the ignition devices 2 and 3 are connected to an electronic control unit 100 by lines 22 and 32, respectively. In this case, in the control system mentioned above, there may be generated an erroneous connection, for example, that the line 22 from the ignition device 2 for an ignition plug 81 provided in a certain cylinder 41 corresponding to a first cylinder, and the line 32 from the ignition device 3 for an ignition plug 82 provided in a cylinder 42 corresponding to a second cylinder are inversely connected to input terminals provided in the electronic control unit 100.
In this case, the ignition of the first cylinder is executed when the injection of the second cylinder is carried out by the electronic control unit 100, and the ignition of the second cylinder is executed when the injection of the first cylinder is carried out. Accordingly, there is a problem that a malfunction of the engine operation is caused, and an emission defect is caused. However, in the fuel injection system of the general-purpose engine in which an inexpensiveness is required by a simple structure, a cylinder discriminating means such as a crank angle sensor or the like is not arranged generally, and the system is not provided with a function of detecting the erroneous connection or correcting the timing of the fuel injection, so that it is impossible to avoid the emission defect and it is not easy to specify its cause.